The pickup truck is one of the world's most widely-used utility vehicles. The pickup's boxlike bed can be adapted to carry an almost limitless variety of cargoes. The rear sidewall of the bed is usually a drop-down tailgate that provides both immediate access to the entire width of the bed and a convenient working surface for tradesmen, farmers, ranchers, and other users.
Nevertheless, one glaring deficiency of the pickup truck is the awkwardness of loading and unloading cargo. The bed itself is above knee level and the top of a sidewall may be at chest level. If the bed is uncovered, lightweight items can be lifted over a sidewall. However, heavy items are usually dragged into or out of the rear of the vehicle, over the tailgate. If the bed is covered, as is commonly done for weather protection and security, every item must cross the tailgate.
A person moving cargo in or out of a pickup bed is therefore often forced to crawl or slide over the tailgate in an unnatural posture while carrying a significant amount of weight. Such actions can cause serious and permanent back and joint injuries. Even in the absence of injury, repeatedly entering and exiting a pickup bed can be exhausting and time-consuming.
The awkwardness and strain of loading and unloading a pickup bed can be reduced by providing a step that allows a user to remain upright while stepping up onto the tailgate. Many users have carried step stools, step ladders, and other such devices for this purpose. However, a stool or ladder may be of insufficient height or strength, difficult to position securely on uneven ground, inadvertently kicked out of position, and may become just another annoying, hard-to-reach piece of junk rattling around in the back of the vehicle.
A step that is attached to a tailgate provides a more elegant solution to the problem. Many such steps are known in the art. Most fold against the tailgate by rotating about fixed pins. Several are aftermarket add-ons that bolt or screw to the top edge of the existing tailgate. While these are relatively easy to install on existing tailgates, they protrude from a tailgate even when not in use and some concentrate all loads on two small, unreinforced attachment points. A tradesman carrying a full load of equipment and material can exceed 300 pounds, and when this force is leveraged through the frame of a step against fasteners attached only to relatively soft vehicle body metal, the result can be catastrophic failure.
Building a tailgate step into a tailgate can reduce the profile of a step when the step is not in use. A typical built-in step is designed to retract into the tailgate, usually on rails or within tubes through the top edge of the tailgate. However, the cross-section and shape of a tailgate often places restrictions on the size and strength of a step mechanism that can be installed within the tailgate. A retractable tailgate step that dangles freely from the edge of a tailgate can be dangerous for a user, but a tailgate step designed to be rigid when in service usually places great stress upon relatively small rails and sliding hinge pins.
Additionally, a tailgate on a working vehicle may be repeatedly doused with water, paint, corrosive solutions and compounds, particulate matter, and a wide variety of other substances that may jam rails and other closely-fitted mechanical parts. Installation of such mechanisms within the interior of a tailgate also creates internal cavities and passages that allow contaminants to enter the tailgate and collect in places where they cannot easily be removed, accelerating structural damage to the tailgate.